Optimisation of FLUKA's cyclotron model for safety assessments: accuracy and uncertainty analysis in neutron ambient dose equivalent H*(10)

A Monte Carlo model using the FLUKA code was developed to streamline dosimetry studies for proton cyclotrons, specifically for the IBA Cyclone®18. The model simulates two liquid targets - Large Volume Silver and Nirta®Conical8 niobium - allowing precise neutron fluence calculations in the vault room. The accuracy of the neutron ambient dose equivalent, H*(10), was validated using experimental data, with results showing strong agreement. The uncertainty analysis indicated a statistical error of less than 10% for neutron dose equivalent and 0.1% for neutron fluence. This model provides a reliable tool for optimising cyclotron installation safety, offering accurate neutron dosimetry with minimal statistical errors.